Evidences of western bean cutworm (Lepidoptera: Noctuidae) overwintering in Quebec (Canada)

The western bean cutworm (WBC), Striacosta albicosta (Smith), is an important corn pest in North America. In the 2010s, WBC has invaded the province of Quebec (Canada) and until now, there was no evidence this pest could overwinter in this province.
In 2017 and 2018, experiments were conducted in three agricultural regions in Quebec. In each site, mature WBC larvae were placed in three storage totes containing sandy soil. One storage totes was removed before the first frosts and another one after and last frosts. An emergence cage was installed over the third tote the following spring to evaluate if WBC adults could emerge. In the spring of 2019, car shelters were also installed in two different sites to validate that moths emergence in fields.
Our results showed that WBC larvae survived to winter conditions in Quebec and moths also emergenced from the fields. These experiments constitute the first demonstration that WBC can overwinter and complete its life cycle under Quebec’s cold climate conditions. It also documents the northernmost overwintering survival for this species in North America.